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A187714
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Odd numbers m divisible by 3 such that for every k >= 1, m*2^k - 1 has a divisor in the set {5, 7, 11, 13, 17, 19, 31, 37, 41, 61, 73, 109, 151, 241, 331}.
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%I #23 Apr 03 2023 10:36:12
%S 7148695169714208807,17968583418362170239,26363076126393718191,
%T 57376760867272385247,67950587841687767283,73873959473901564111,
%U 81055172741266754727,96217896533288105991,104173338506128098489
%N Odd numbers m divisible by 3 such that for every k >= 1, m*2^k - 1 has a divisor in the set {5, 7, 11, 13, 17, 19, 31, 37, 41, 61, 73, 109, 151, 241, 331}.
%C Wilfrid Keller (2004, published) gave the first known example.
%C 7148695169714208807 computed in 2017 by the author.
%C Conjecture: 7148695169714208807 is the smallest Riesel number that is divisible by 3. - _Arkadiusz Wesolowski_, May 12 2017
%H Chris Caldwell, The Prime Glossary, <a href="https://t5k.org/glossary/xpage/RieselNumber.html">Riesel number</a>
%H Carlos Rivera, <a href="http://www.primepuzzles.net/problems/prob_049.htm">Problem 49</a>
%Y Cf. A101036, A187716.
%K nonn
%O 1,1
%A _Arkadiusz Wesolowski_, Mar 17 2011
%E Name changed and entry revised by _Arkadiusz Wesolowski_, May 11 2017
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